667766401 has 2 divisors, whose sum is σ = 667766402. Its totient is φ = 667766400.

The previous prime is 667766399. The next prime is 667766413. The reversal of 667766401 is 104667766.

667766401 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 345922801 + 321843600 = 18599^2 + 17940^2 .

It is a cyclic number.

It is not a de Polignac number, because 667766401 - 2¹ = 667766399 is a prime.

Together with 667766399, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (667766471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333883200 + 333883201.

It is an arithmetic number, because the mean of its divisors is an integer number (333883201).

Almost surely, 2^667766401 is an apocalyptic number.

It is an amenable number.

667766401 is a deficient number, since it is larger than the sum of its proper divisors (1).

667766401 is an equidigital number, since it uses as much as digits as its factorization.

667766401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 254016, while the sum is 43.

The square root of 667766401 is about 25841.1764631566. The cubic root of 667766401 is about 874.0605540626.

The spelling of 667766401 in words is "six hundred sixty-seven million, seven hundred sixty-six thousand, four hundred one".